(a) Field of the Invention
This invention relates to a novel process that permits the unexpectedly efficient and convenient preparation of antiarrhythmic 1,3-diazabicyclo[4.4.0]dec-2-en-4-ones (hereinafter "diazabicyclodecenones") of Formula II of the copending U.S. patent application, Ser. No. 06/635,989, now U.S. Pat. No. 4,560,754, having the same assignee as the present application, using 1-acyl-.alpha.-[2-[bis(1-methylethyl)amino]ethyl]-.alpha.-phenyl-2-piperid ineacetamides of Formula I. ##STR1## More specifically, this invention relates to a process for preparing diazabicyclodecenones of Formula II in improved overall yield and purity by acylating .alpha.-[2-[bis(1-methylethyl)amino]ethyl]-.alpha.-phenyl-2-piperidineacet amides and then treating the resultant 1-acyl-.alpha.-[2-[bis(1-methylethyl)amino]ethyl]-.alpha.-phenyl-2-piperid ineacetamides of Formula I with a strong base in a polar organic solvent.
This invention also relates to the 1-acyl-.alpha.-[2-[bis(1-methylethyl)amino]ethyl]-.alpha.-phenyl-2-piperid ineacetamides of Formula I employed in the preparation of the antiarrhythmic diazabicyclodecenones of Formula II.
(b) Prior Art
Antiarrhythmic 1,3-diazabicyclo[4.4.0]dec-2-en-4-ones of Formula II have been disclosed in European patent publication No. 104,647, filed Sept. 27, 1983, and in copending U.S. patent application, Ser. No. 06/635,989, now U.S. Pat. No. 4,560,754, both having the same assignee as the present application. The process of this invention and the 1-acyl-.alpha.-[2-[bis(1-methylethyl)amino]ethyl]-.alpha.-phenyl-2-piperid ineacetamides, Formula I, of this invention were disclosed but not claimed in copending Ser. No. 635,989.